Clips of the foregoing nature are well known in commerce, and may be generally exemplified by the clips described in U.S. Pat. Nos. 4,887,335, and 6,058,572, of common inventorship herewith. The clips in general comprise a pair of axially extending jaws which are interconnected at one end by a hinge so as to be swingable between an open position and a closed position, in which confronting portions of the jaws are in proximity, and a latch at the axially opposed end for releasably retaining the jaws closed. For economy of manufacture the hinge is typically a live hinge (also known as a living hinge). However, such form of hinge is not always suitable, for example where it is desired to form the clip from a material with a relatively high modulus of elasticity. Also, it is not always convenient or desired that the clip be molded as a unitary structure.
It is known to form clips which are generally of the foregoing type, but in which the jaws are connected through a hinge pin. In early examples of such clips, the hinge pin was inserted through interleaved gudgeon openings associated with the jaws, in a machine operation. In U.S. Pat. No. 5,050,272 there is described a clip wherein the jaws may be snap assembled together in a hand operation. In this clip one of the jaws is channeled, and the opposing jaw comprised a rib which interleaves in the channel when the jaws are closed. The hinge pin is integrally molded with the channeled jaws to span between opposed side walls thereof, and the rib is provided with a downwardly open slot within which the pin is engagable. The geometry of the arrangement is such that it reduces the size of a bag that can be closed by the clip in comparison to a similar sized clip with a living hinge. Additionally, the axial end of the channeled jaw is open at the hinge pin end, to permit the pin to be molded integrally with the jaw. Accordingly, the channeled jaw may be highly stressed when the clip is in use, leading to a possible failure of the clip. Still further, if the jaws of the clip are fully opened, the one jaw will act as a fulcrum, and the slot of the ribbed jaw will disengage from the hinge pin. Moreover, while it is not uncommon that one at least of the jaws of a clip be formed with the requisite channel structure, this is not necessarily the case.
In all clips of the foregoing nature, reactive forces are generated as the jaws of the clip are closed about a bag or the like. Where the clip is intended for use for closing heavy bags or sacks, which may have a contents in the range of about 25 to 50 kg, the jaws may typically have a length of some 250 mm, and strong reactive forces may be generated sufficient to displace the jaws in the axial direction. This may result in the failure of the latch elements to engage together, and where the hinge is of a snap together type, in the disengagement of the hinge elements.
Many comestible and other products are sealed in bags or the like for sale to the consumer; the bags must be opened, usually with a knife or scissors, to gain access to the contents, following which the bags may be closed by the clips to which the invention relates. It would be desirable to provide in a clip one or more accessory functions, for example a slitter to slice open a bag, or a measuring scoop or cup to facilitate the removal of a measured amount of product from the bag, or a handle to facilitate the handling of the bag, particularly where this may be heavy.
It is a prime object of the invention to provide a clip with a snap together hinge which has a closure capacity at least equal to that of a comparable clip with a living hinge.
It is another object of this invention to provide a clip with a snap together hinge which will resist the tendency for disengagement if over-rotated.
It is still another object of the invention to provide a clip with a snap together hinge which will resist the tendency of the jaws to be axially displaced under heavy loads.
It is yet another aspect of the invention to provide in a clip a snap together hinge which is relatively independent of the jaw structure.
It is a further object of this invention to provide a clip having different modes of operation.
It is a still further object of this invention to provide a clip having one or more accessory functions.